Table 2.

Model fit indexes and comparison for different models of the relationship between internet addiction and depression and delinquency.

Models	χ2	df	CFI	TLI	RMSEA (90% CI)	SRMR	Model comparison	∆χ2	∆df
Model 1: No cross-lagged effects	153.132	15	0.958	0.908	0.056 (0.048, 0.064)	0.045
Model 2: Internet addiction effects	82.042	13	0.979	0.947	0.043 (0.034, 0.052)	0.028	M2 vs. M1	71.09***	2
Model 3: Depression and delinquency effects	120.845	13	0.967	0.917	0.053 (0.045, 0.062)	0.037	M3 vs. M1	32.29***	2
Model 4: Reciprocal effects	56.517	11	0.986	0.959	0.038 (0.028, 0.048)	0.020	M4 vs. M1	96.62***	4
							M4 vs. M2	25.53***	2
							M4 vs. M3	64.33***	2
Multi-group (boys vs. girls) tests on the reciprocal model
Model 4a: Unconstrained model	48.050	16	0.990	0.966	0.037 (0.025, 0.049)	0.022
Model 4b: Constrain internet addiction → depression	48.827	17	0.990	0.969	0.036 (0.024, 0.048)	0.022	M4b vs. M4a	0.77	1
Model 4c: Constrain internet addiction → delinquency	55.730	17	0.988	0.962	0.039 (0.028, 0.051)	0.024	M4c vs. M4a	7.68**	1
Model 4d: Constrain depression → internet addiction	54.975	17	0.988	0.963	0.039 (0.028, 0.051)	0.023	M4d vs. M4a	6.93**	1
Model 4e: Constrain delinquency → internet addiction	48.156	17	0.990	0.969	0.035 (0.024, 0.047)	0.022	M4e vs. M4a	0.11	1
Model 4f: free internet addiction → delinquency, and depression → internet addiction, constrain other paths (final model)	48.934	18	0.990	0.971	0.034 (0.023, 0.046)	0.022	M4f vs. M4a	0.88	2

^**p<0.01;

^***p<0.001.